When someone mentions pollution, it often conjures images of Beijing city skies, people choking on exhaust fumes, maybe wearing masks as they walk down the street. The scary truth is, the air in your home is just as dangerous as the air outside–maybe worse.

The main culprit is what is scientifically known as particulate matter (PM). It’s a fancy term for really little floating stuff. It gets caught in your lungs, and we’re starting to realize that these little pieces of… stuff are causing lung cancer, heart attacks, and all manner of pulmonary problems. There’s a very good chance that they are affecting us on a cellular level as well. The World Health Organization (WHO) estimates that PMs cause about 800,000 premature deaths every year. But even if it does kill you, studies are showing that bad air actually makes you dumber.

PMs inside your home come from all sorts of things, and many of them are extremely difficult to avoid. Even cooking releases tiny micro bits of matter into the air that you end up breathing in for days. But your appliances have exhaust (even just a little bit) that contributes as well.

Then there’s radon, the second biggest cause of lung cancer in the U.S. And there’s nothing you can do to prevent it. It comes from the natural degradation of certain rocks and soils that might be under your house.

And don’t get us started on mold. It’s one of the major contributors to severe toxicity in people, and something that I have spent a lot of time with a lot of patients getting rid of.

And now you’re freaked out. So much doom and gloom! Well, there are silver linings. One is that builders and engineers are starting to make homes more airtight. This is mostly done for energy conservation purposes, but one of the good unintended consequences is that outside influences (like radon or pollution from the atmosphere) are getting in less and less. Plus, if you’re living in a newer home built with energy conservation in mind, you probably don’t have much to worry about by way of mold.

And if you’re fortunate enough to be working in a newer office building, recent trends have them already equipped with air sensors, and even nowadays, builders compete with each other for indoor air health and safety ratings. Things are turning around for the better.

But if you’re living in an older home, there are some measures you should probably be taking to ensure you’re protecting yourself.

You can get this nifty little device called “The Speck” that measures the air quality in your home. It’s only about $150 and well worth it. You should also be working with an air filter in your home, just out of principle. Just a simple commercial air filter has been shown to reduce a C-reactive protein in the blood by 30 percent. This protein is indicative of inflammation, so less is better. It’s well worth the trouble, and you just sort of feel cleaner when you’ve got one.

Consider upgrading your filtration and ventilation systems. If you’re renting, talk to your landlord about it. This can go a long way in protecting your health and should be treated as importantly as a leaky roof or a broken furnace.

Monitor yourself for symptoms. Do you feel allergic to something in your home, but you’re fine when you leave? It might be mold, which also manifests in flu-like symptoms. Radon poisoning manifests as lung issues. You’ll develop a persistent cough, chest pain, and shortness of breath. If you start to notice these things (I’m talking to you, fellas), don’t just ignore them or chalk them up to “getting older.” Test the quality of the air in your home and/or office.

One thing I often think: modern society has not changed the state of mankind all that much. We must be constantly vigilant. Perhaps our ancestors had to be on the lookout for rival tribes or saber-toothed tigers. They used a constantly-burning fire to keep themselves safe. We have to be vigilant of the many, many threats that have arisen from our industrial society. But our tools are gadgets and building materials. Keep your eyes open out there people.

Dr. Sarah Ernst, D.C. is the founder of Prosperity Health. She is a cellular detoxification coach and chiropractor. She has obtained countless hours of training in cellular detoxification, functional endocrinology, and female hormone issues.